THE FIIOG 6'-'jh 



receives mixed blood results first in a relativeljf low body tem- 

 perature and, second, in slow chemical changes in the body — 

 a sluggish life. 



Organs of Excretion and Reproduction. — Tlie two kidneys 

 (Fig. 313, kd) lie in the dorsal part of the body cavitj'. They 



-VTs-.. 



Fig. .31.5. — Aurode, Salamandra maculosa, of Europe, showing exter- 

 nal ringed condition of the body. After Cuvier. 



consist of a mass of tubules closel.y intertwined with 

 blood-vessels that yiekl their waste products to the 

 tubules from which they pass by the ureters to the 

 cloaca. 



The male germ glands (fs) he at the anterior end 

 of the kidney's and their products ]:iass through c(>r- 

 tain tuliules of the kidney and so, by way of the 

 ureters, to the cloaca. Thus certain of the excretory tubules 

 serve in the frog, as in annelids, to carry the germ cells to the 

 exterior. 



The ovaries of the frog are large sacs covering the kidneys. 

 The ripe eggs fall from the ovary into the bodj^ cavity, are 

 picked up by the oviducts which open into the body cavity. 



